Bi-axial texturing of high-K dielectric films to reduce leakage currents

1. A method of forming a transistor on a semiconductor substrate, the method comprising: forming a channel region between a source region and a drain region of a semiconductor substrate; forming a high-K dielectric gate dielectric layer on the channel region, the layer comprising a high-K dielectric film having a first crystal lattice structure defining a first grain and a second crystal lattice structure defining a second grain, the lattice structures defining an associated grain boundary at the intersection of the first and second grains and wherein at least two axes of the first grain are substantially aligned with corresponding axes of the second grain at the associated grain boundary; forming a remaining portion of a gate stack on the high-K dielectric gate dielectric layer in the channel region between the source region and the drain region; and forming a gate electrode coupled to the gate stack.

2. The method of claim 1 wherein the grains of the high-K dielectric film are formed to include a, b, and c axes and wherein the c axes of the first and second grains are substantially parallel to each other.

3. The method of claim 1 wherein the grains of the high-K dielectric film are formed to include a, b, and c axes and wherein the c axes of the first and second grains are normal to a top surface of the channel region.

4. The method of claim 1 wherein a semiconductor material used to form the channel, source, and drain regions consists of materials selected from among silicon material or doped silicon material.

5. A method of forming a high-K dielectric film on a semiconductor substrate, the method comprising: providing a semiconductor substrate having a surface in readiness for the formation of dielectric layers; and forming a crystalline high-K dielectric film on the surface of the substrate, the dielectric film having grain boundaries with a high degree of crystallographic alignment at said grain boundaries such that crystallographic misalignments at said grain boundaries are in the range of about 1 to about 15 degrees.

6. The method of claim 5 wherein the high-K dielectric film comprises layers of at least one of: ZrO 2 , ZrSiON, HfO, HfO 2 , HfSiON, HfON, CeO 2 , Dy 2 O 3 , SmO, Sm 2 O 3 , MgO, Y 2 O 3 , Pr 2 O 3 , Al 2 O 3 , La 2 O 3 , Na 2 O 3 , Eu 2 O 3 , Gd 2 O 3 , Tb 2 O 3 , Ho 2 O 3 , Er 2 O 3 , Tm 2 O 3 , Yb 2 O 3 , Lu 2 O 3 and Hf 0.74 Yb 0.26 O 1.8 .

7. The method of claim 6 wherein the high-K dielectric film comprises layers of at least one of: ZrO 2 , ZrSiON, HfO, HfSiON, HfON, SmO, Al 2 O 3 , Na 2 O 3 , and Hf 0.74 Yb 0.26 O 1.8 .

8. The method of claim 5 wherein the high-K dielectric film comprises layers of at least one of: ZrO 2 , HfO, SmO, Al 2 O 3 , and Hf 0.74 Yb 0.26 O 1.8 .

9. The method of claim 5 wherein the high-K dielectric film includes a first crystal lattice structure having a first grain and a second crystal lattice structure having a second grain defining therebetween an associated grain boundary and wherein at least two axes of the first crystal grain are aligned to within about 1 degrees to about 15 degrees of corresponding axes of the second grain at the associated grain boundary.

10. The method of claim 9 wherein the at least two axes of the first grain are aligned to within about 1 to about 5 degrees of corresponding axes of the second grain at the associated grain boundary.

11. The method of claim 5 wherein forming the high-K dielectric film comprises employing a deposition process in conjunction with an ion beam assisted grain orientation control process to form the high-K dielectric film wherein the ion beam assisted grain orientation control process includes bombarding the substrate with ions from an ion beam directed onto the substrate at a specified bombardment angle.

12. The method of claim 5 , wherein forming the dielectric film having a high degree of crystallographic alignment at said grain boundaries comprises ion beam treating the film to preferentially erode crystallographically misaligned high-K dielectric material thereby forming the high-K dielectric film.

13. The method of claim 11 , wherein the specified bombardment angle is related to the crystallographic lattice structure of the high-K dielectric material used to form the high-K dielectric film.

14. The method of claim 11 , wherein the high-K dielectric material is one of hafnium dioxide and zirconium dioxide and the specified bombardment angle is about 35 degrees.

15. The method of claim 12 , wherein the high-K dielectric material forms a face centered cubic structure and the specified bombardment angle is about 35 degrees.

16. The method of claim 11 , wherein the deposition process includes one of atomic layer deposition (ALD), metal organic chemical vapor deposition (MOCVD), physical vapor deposition (PVD), and plasma enhanced chemical vapor deposition (PECVD).

17. The method of claim 11 , wherein the deposition process includes one of low pressure CVD, evaporation, laser ablation, molecular beam CVD, and molecular beam epitaxy (MBE).

18. The method of claim 11 wherein the high-K dielectric crystalline film includes crystalline structures have a desired crystallographic orientation and the ion beam is directed onto the substrate at a bombardment angle associated with a relatively high atomic density for the crystalline structures having the desired crystallographic orientation thereby promoting the formation of crystalline structures having the desired crystallographic orientation and a high degree of crystallographic alignment at the grain boundaries.

19. The method of claim 11 , wherein the deposition process and ion beam assisted grain orientation control process used to form the high-K dielectric film forms a dielectric film having a substantially aligned high-K dielectric crystal lattice structure; and wherein bombarding the substrate with an ion beam comprises selecting the specified bombardment angle such that the ions from the ion beam preferentially erode deposited material that is not substantially aligned with the high-K dielectric crystal lattice structure thereby facilitating the formation of a dielectric film having substantially aligned high-K dielectric crystal lattice structures.

20. The method of claim 11 , wherein the deposition process and ion beam assisted grain orientation control process used to form the high-K dielectric film includes directing the ion beam onto the substrate at a bombardment angle chosen to facilitate the formation of a dielectric film having substantially aligned high-K dielectric crystal lattice structures.

21. The method of claim 11 , wherein the deposition process and ion beam assisted grain orientation control process form the high-K dielectric film in a manner calculated to form a substantially aligned high-K dielectric crystal lattice structure; and wherein selecting the specified bombardment angle comprises selecting the specified bombardment angle such that the ions from the ion beam preferentially erode crystallographic structures that are not aligned with the substantially aligned high-K dielectric crystal lattice structure.

22. The method of claim 21 , wherein the deposition and ion bombardment operations are performed contemporaneously.

23. The method of claim 21 , wherein the deposition and ion bombardment operations are performed in alternating deposition steps and bombardment steps.

24. The method of claim 23 , wherein alternating deposition and ion bombardment operations are performed as part of an ALD process.

25. The method of claim 5 wherein forming the high-K dielectric film comprises employing an angular deposition process in which at least some deposited materials used to form the high-K dielectric film are deposited onto the substrate at a deposition angle chosen such that the resultant high-K dielectric film is formed with a high degree of crystallographic alignment at grain boundaries of the resulting dielectric film.

26. The method of claim 25 wherein the deposition process used to form the high-K dielectric film is selected from among a sputter deposition process, a physical vapor deposition process (PVD), and a plasma enhanced chemical vapor deposition (PECVD) process.

27. A method of forming a high-K dielectric film on a semiconductor substrate, the method comprising: providing a semiconductor substrate having a surface in readiness for the formation of dielectric layers; and forming a high-K dielectric film on the surface of the substrate, wherein the dielectric film is formed having at least two high-K dielectric crystals having grain boundaries at the intersection of the crystals and wherein the crystallographic lattice axes of the crystals are slightly misaligned at the grain boundaries wherein said misalignment is on the order of about 1 degree to about 15 degrees.

28. The method of claim 27 wherein each of the crystals have three lattice axes arranged in accordance with the crystallographic structure of the crystals and wherein forming a high-K film comprises forming the film so that at least two of the lattice axes are substantially aligned at the grain boundaries.

29. The method of claim 27 wherein the at least two axes of the first crystal are aligned to within about 1 degree to about 5 degrees of corresponding axes of the second crystal at the associated grain boundary.

30. A method of forming a high-K dielectric film on a semiconductor substrate, the method comprising: forming a crystalline high-K dielectric film on a surface of a semiconductor substrate wherein the surface is in readiness for the formation of a dielectric layer, wherein the dielectric film is formed having grains that intersect at grain boundaries such that the crystallographic orientation of the grains is subject to small variations in biaxial alignment at the grain boundaries so that the small variations define low intersection angles for crystallographic lattices of the grains at the grain boundaries, the low intersection angles being in the range of about 1 degree to about 15 degrees.

31. The method of claim 30 wherein the low intersection angles are in the range of about 1 degrees to about 5 degrees.

32. The method of claim 30 wherein forming the dielectric film comprises: depositing a high-K dielectric precursor onto the substrate; directing an ion beam onto surface at a bombardment angle arranged to preferentially erode materials that are not substantially bi-axially aligned with selected crystal lattice structures; and reacting the low-K dielectric precursor to form a desired layer of high-K dielectric material.

33. The method of claim 30 wherein forming the dielectric film comprises: depositing a high-K dielectric precursor onto the substrate; directing an ion beam onto surface at a bombardment angle corresponding to an angle of a selected crystal lattice structure having a high resistance to ion beam erosion relative to other bombardment angles thereby facilitating preferential erosion of the dielectric film for crystal structures that are not substantially bi-axially aligned with the selected crystal lattice structures thereby allowing the formation of substantially bi-axially aligned crystal lattice structures associated with the bombardment angle corresponding to an angle of a selected crystal lattice structure; and reacting the low-K dielectric precursor to form a desired layer of high-K dielectric material.

34. The method of claim 33 wherein directing the ion beam onto surface at a bombardment angle corresponding to an angle having a high resistance to ion beam erosion relative to other bombardment angles comprises directing the ion beam onto the substrate at an angle characterized by high atomic density for the crystal lattice structure associated with the high-K dielectric material used to form the high-K dielectric film.